The dog ended up in an unknown place.
After god knows how long he finally woke up and became aware of his surroundings.
All the light in the room came from two windows on the top of the wall, after scouting the room he noticed an opening in one of the walls. His immediate decision was to take a look inside it.
At first glance he couldn't see much, but after his eyes got adjusted to the darkness he could see a stairway leading to a rusty, metal door.
He climbed up the flight of stairs leading to the door with the optimism that he would find way out. On closer inspection the door looked damaged really bluntly, as if it had received many desperate blows. After the dog was done observing his surroundings he finally decided to get out of there. On his first push the door did not move an inch, and panicked thoughts started flooding his mind. He had to think of someway to pry it open, so he went back down to search for a tool or anything that can help him, however besides rubbish that was no good to him, he couldn't find anything useful. At last he couldn't do anything else but ram the door and hope that it would break off its hinges, so he started throwing his body against it time and time again. The withered old door couldn't take the constant barrage of slams on its hinges and frames. With one last push the old walls couldn't hold the weight of the door and the hinges broke loose!
The switch from a super dark environment to beams of light blinded the dog for a moment and he relapsed.He took a step outside and wagging his tail in excitement before he saw what was waiting for him on the other side.